2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 135
Circuit/System Description
Stepper motors are used for temperature regulation, air distribution control and recirculation door control.
With the appropriate switches at the Radio/HVAC control, the desired air temperature door position, air distribution door position and recirculation
door position can be put in. The selected values are passed to the HVAC control module via the LIN-Bus. The HVAC control module supplies a 12
V reference voltage to the stepper motors and energizes the 4 stepper motor coils with a pulsed ground signal. The stepper motors put the
appropriate door into the calculated position, in order to reach the put in temperature/position.
Conditions for Running the DTC
* Ignition ON.
* The HVAC control module is ON.
Conditions for Setting the DTC
B023A 02
The stepper motors supply output is shorted to ground.
B0223 01, B022A 01, B0233 01, B0408 01, B0418 01, B0428 01 or B3531 01
At least one control output (of four possible outputs) of the appropriate stepper motor is shorted to voltage when motor starts moving. Faults are not
detected when motor is already running or target position is already reached.
B0223 06, B022A 06, B0233 06, B0408 06, B0418 06, B0428 06 or B3531 06
At least one control output (of four possible outputs) of the appropriate stepper motor is shorted to ground or open when motor starts moving.
Faults are not detected when motor is already running or target position is already reached.
Action Taken When the DTC Sets
B023A 02
* The affected output will be switched off for hardware protection.
* All stepper motors are deactivated.
B0223, B022A, B0233, B0408, B0418, B0428 or B3531
* The affected output will be switched off for hardware protection.
* The affected stepper motor is deactivated.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
HVAC Schematics (See: Heating and Air Conditioning/Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
Automatic HVAC Description and Operation (See: Heating and Air Conditioning/Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
